Many industrial processes, such as combustion and chemical oxidation, require enriched air as a process input. Often the enriched air is required by the industrial process at a relatively high pressure, typically at a pressure much higher than that at which an air separation plant operates. This creates an inefficiency.
Accordingly it is an object of this invention to provide a system for producing enriched air, especially relatively high pressure enriched air, which employs a cryogenic air separation plant and which operates with improved efficiency over conventional systems for providing enriched air.